An equation of a quadratic function in standard, y=a(x-p)^2+q, can be expanded and written in general form, y=ax^2+bx+c. When the equation of a quadratic function is in general form, most characteristics of the graph cannot be identified. For the reason, it is useful to be able to convert from general form to standard form. This can be done by “completing the square”. This process involves including a perfect square in the equation of the quadratic function.

4.7 Modelling and solving problems with quadratic functions

This chapter is use of chapter 4.1~4.6 technology. Some problems can be solved by writing, then graphing a quadratic function.